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05-08-15 08:13 PM
Re: More power for LMS Ultra 5400s?

Glad ya got it figured out, and are happy with the result ham.

Thanks for the info.
05-07-15 10:46 PM
Re: More power for LMS Ultra 5400s?

So what I did is buy a CleanBox. I put it in the system set with the gains at the midpoint, with balanced audio cables to the amps, and set the gain on the ep2500s to the midpoint as well. I calibrated the subs individually to 70 dB, to match the rest of the system. That was achieved with a Lex setting of -6 dB.

I took the Clean Box out of the system and recalibrated with just the Lex going to the subs. To achieve the same dB level, without changing the Clean Box or ep2500 settings, the Lex had to go up to +6 dB, consistent with the gain provided by the Clean Box.

I was surprised to note that there was a definite difference in the subs' output with the Clean Box. They not only seemed fuller, but the very very low sub extension was much more pronounced with the Clean Box, and was not only audible but visually and palpably improved. I can only speculate that the Lex output will clip with substantial sub output when set at +6 dB gain, and by lowering the gain the Clean Box allowed much more headroom.

In any event, the Clean Box is a definite improvement to the system. The ep2500s do not seem to be clipping (no red lights) and the subs are really working well. Not sure if I need more power at this point -- thanks, Craig, anyway, for the link -- but I might wind up needing hearing aids!

Thanks for all the suggestions. I will try to dig up the specs on the cabinets and post them later. Any further comments would be welcome.
05-02-15 04:12 PM
Re: More power for LMS Ultra 5400s?

ham - if you would like to try out one of our MQ-600 amps, let me know. Bridged mono, it will deliver an honest 2000 watts into 4 ohms. Based on my experience - and that of others who have compared them - it's quite the step up from a EP-2500.

Here is a link to the spec page ... and yes, it is a 50 pound beast.


There would be no risk to you ... if you like it, you pay $450 including shipping to you. If not, we will pay return shipping.
05-02-15 02:55 PM
ham Wayne,

The way I have calibrated my surround system is to put the pre/pro in calibration mode. It then sends a test tone to each of the seven speakers, and then the subs, in sequence. The volumes are set to match with a dB meter. From my reading, various levels are used; I chose 70 dB spl. I also measured the distances etc.

I have calibrated the subs to each other and the room using the SVS Audyssey unit to get flat response. The subs achieve this 70 dB level, and so that is why I have thought they were correctly calibrated and that there was no issue with the pre/pro output level. However, they don't really produce the level of bass that I, subjectively, feel they should. Hence my question-- is this the right way to do it? If not, what am I missing? Do I just crank it up until I think "it's right," or is there a better way?
05-02-15 12:58 PM
dougc I made a ramp out of eight 6x8 boards, strapped a furniture dolly to the cabinet, and hoisted them up the ramp with an electric engine jack. It was really very easy. Getting them spaced just right for the best response took and eight hour day of moving and measurements.
05-01-15 12:22 PM
Re: More power for LMS Ultra 5400s?

If these are the GHorns I am thinking about, there is a picture showing the guys pulling and pushing them up the pull down stairs to the attic.
Pretty amusing.
04-30-15 08:26 PM
Re: More power for LMS Ultra 5400s?

dougc wrote: View Post
I have two DIY horns called Gjallarhorns that have a BW18 high pass at 13hz with a balanced MiniDSP and are lowpassed to my mains at 80hz. I have them mounted in the ceiling at 1/4 points in the room and each is run off of a channel of a clone amp. They are pretty big at around 45x45x25" and incredibly heavy.
You have a pair of ghorns in your ceiling?! You are one dedicated basshead my friend. How on earth did you mount them?
04-30-15 03:01 PM
Wayne A. Pflughaupt
Re: More power for LMS Ultra 5400s?

ham wrote: View Post
Wayne, I thought about pushing the output on the pre/pro higher, but maybe it is worth getting a bump box?
Only if your sub output is maxed out.

The subs come up to 70 dB pink noise easily when the Lex is going through calibration for each speaker, which is what made me think there was too little power.
I have no idea what you mean by “comes up to 70dB easily,” or why that would indicate a low signal input.

04-29-15 03:58 PM
Re: More power for LMS Ultra 5400s?

What is the tune of your cabs? I should add that a proper HPF is VERY important when using ported cabinets, especially when adding more power.

I have two DIY horns called Gjallarhorns that have a BW18 high pass at 13hz with a balanced MiniDSP and are lowpassed to my mains at 80hz. I have them mounted in the ceiling at 1/4 points in the room and each is run off of a channel of a clone amp. They are pretty big at around 45x45x25" and incredibly heavy. I am very happy with the sound. Here's a FR without EQ (in red) and a couple pics of them.

04-29-15 03:05 PM
ham Regarding MLP, the position is about 3 feet for midline on a couch about 13 feet from the screen. So, the subs are about 16 feet from MLP to the left and maybe 14 feet to the right.

Doug, that is an amazing set up. Not to digress from my own thread, but could you post a picture or a link? Do you have a clone amp, and how have you set it all up?
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